User guide

Chapter 22: Scaler II MegaCore Function 22–5
Parameter Settings
January 2013 User Guide
Algorithm Settings
Scaling algorithm
Nearest Neighbor,
Bilinear, Bicubic,
Polyphase, or
Edge Adaptive
Choose the scaling algorithm. For more information about these
options, refer to , “Nearest Neighbor Algorithm” on page 21–1,
“Bilinear Algorithm” on page 21–2, “Polyphase and Bicubic
Algorithms” on page 21–3, and “Edge-Adaptive Scaling
Algorithm” on page 22–2.
Enable post scaling
sharpen
On or Off Turn on to include a post-scaling edge-adaptive sharpening filter.
Always downscale or
pass-through
On or Off
Turn on if you want the output frame height to be less than or
equal to the input frame height, which reduces the size of the line
buffer by one line.
If the input height becomes less than the specified output height
for any reason, the output video is undefined but it must still have
the correct dimensions and the core must not crash.
Share horizontal and
vertical coefficients
On or Off
Turn on to force the bicubic and polyphase algorithms to share the
same horizontal and vertical scaling coefficient data.
Vertical filter taps 4–64, Default = 8
Choose the number of vertical filter taps for the bicubic and
polyphase algorithms.
Vertical filter phases 1–256, Default = 16
Choose the number of vertical filter phases for the bicubic and
polyphase algorithms.
Horizontal filter taps 4–64, Default = 8
Choose the number of horizontal filter taps for the bicubic and
polyphase algorithms.
Horizontal filter phases 1–256, Default = 16
Choose the number of horizontal filter phases for the bicubic and
polyphase algorithms.
Default edge threshold
0 to 2
bits per symbol
–1,
Default = 7
Choose the default value for the edge-adaptive scaling mode. This
value will be the fixed edge threshold value if you do not turn on
Enable run-time control of input/output frame size and edge/blur
thresholds.
Default upper blur limit
0 to 2
bits per symbol
–1,
Default = 15
Choose the default value for the blurred-edge upper threshold in
edge-adaptive sharpening. This value will be the fixed threshold
value if you do not turn on Enable run-time control of
input/output frame size and edge/blur thresholds.
Default lower blur limit
0 to 2
bits per symbol
–1,
Default = 0
Choose the default value for the blurred-edge lower threshold in
edge-adaptive sharpening. This value will be the fixed threshold
value if you do not turn on Enable run-time control of
input/output frame size and edge/blur thresholds.
Precision Settings
Vertical coefficients
signed
On or Off
Turn on to force the algorithm to use signed vertical coefficient
data.
Vertical coefficient integer
bits
0–32, Default = 1 Choose the number of integer bits for each vertical coefficient.
Vertical coefficient
fraction bits
1–32, Default = 7 Choose the number of fraction bits for each vertical coefficient.
Horizontal coefficients
signed
On or Off
Turn on to force the algorithm to use signed horizontal coefficient
data.
Table 22–2. Scaler II Parameter Settings Tab
Parameter Value Description